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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

17042 results found.

  1. GRB031203, improved XMM position
  2. XMM-Newton Observations of GRB031203: Preliminary Images
  3. IPN/HETE localization of GRB031203B (=H2949; large error box)
  4. GRB031203: ROSAT upper limits suggest XMM-S1 source as the transient
  5. XMM-Newton Observation of GRB031203
  6. XMM-Newton Observation of GRB031203
  7. GRB 031203: IR NTTobservations do not confirm REM detection
  8. GRB 031203: Apparent Spectral Break
  9. GRB031203: Planned XMM-Newton observation II
  10. GRB 031203: IR REM Observations
  11. GRB031203: Optical Observations
  12. GRB 031203 XMM-Newton observation
  13. GRB031203: Planned XMM-Newton observation
  14. GRB 030329: Planned XMM-Newton Observation
  15. GRB 031111B (= H2925) : Kyoto Optical Observation
  16. GRB 031111, optical observations
  17. XRF031109 (=H2919): A very long XRF localized by HETE
  18. IPN triangulation of GRB031108 (large error box)
  19. GRB031026: 1.2mm upper limit with MAMBO at the IRAM 30m
  20. GRB030929/SN2003jd association unlikely based on IPN localiztion
  21. IPN triangulation of GRB031027 (small error box)
  22. Lulin optical follow-up observations of GRB031026
  23. IPN triangulation of GRB031024 (single error box)
  24. XRF 030824: additional observations at CFHT
  25. XRF 030723: Subaru Optical Observations
  26. XRF 030824: Early follow-up observation at Kiso observatory
  27. XRF 030723: Detection of the likely host galaxy
  28. IPN triangulation of GRB030919 (large error box)
  29. GRB030913: Subaru Optical Observations
  30. GRB 030913, optical candidate
  31. GRB 030913, BOOTES observations
  32. GRB030913: wide field imaging (7 sq.deg) of the error box by MASTER
  33. XRF030824: Optical observations
  34. IPN triangulation of GRB030903 (large error box)
  35. IBAS detection of bursts from SGR 1806-20
  36. Radio Observations of SGR1806-20
  37. GRB030823: optical observation at Tokyo Tech
  38. Lulin follow-up observations of GRB030823
  39. GRB 030817 = H2808 TAROT optical observations
  40. SGR 1808-20 (=H2802): A Possible new SGR
  41. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  42. XRF030723, BVRcIc field photometry update
  43. IPN triangulation of GRB030801 (large error box)
  44. GRB021206 optical counterpart upper limit
  45. IPN triangulation of GRB030726 (large error box)
  46. XRF030723 Radio Observations
  47. XRF 030723: confirmation of fading optical counterpart
  48. XRF030723(=H2777): Chandra Observations
  49. GRB030723: Upper limits from historical observations
  50. XRF030723: Palomar observations and proposed counterpart
  51. XRF030723, BVRcIc field photometry correction
  52. XRF030723, ROTSE-III Early Observations
  53. XRF030723, BVRcIc field photometry
  54. XRF 030723, optical observations
  55. XRF030723, optical observations
  56. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  57. SGR 1806-20, submm observations
  58. RXTE PCA Observations of SGR1806-20 Region
  59. GRB030329: Subaru Optical Spectroscopy
  60. GRB030329, optical observation in May
  61. IPN triangulation of GRB030626 (single large error box)
  62. IPN triangulation of GRB030626 (two large error boxes)
  63. HETE detection of burst from SGR1806-20
  64. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  65. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  66. GRB 030528: tentative NIR counterpart
  67. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  68. GRB030528, BVRI field photometry
  69. GRB030329, SPM optical observations
  70. GRB030528(=H2724): Revised SXC Localization
  71. GRB 030528 Bisei optical observation
  72. GRB 030528 (=H2724) Kyoto optical observation
  73. GRB 030329 Optical Observations
  74. GRB 021004: HST observations
  75. GRB030324: Further Observations of the Candidate Optical Afterglow
  76. HETE GRB030329, correction to Rc Observations in Loiano
  77. GRB 030329: Optical limit (contemporaneous imaging)
  78. IPN triangulation of GRB030509 (single error box)
  79. GRB030429, refiend optical brightness
  80. GRB030418, BVRcIc field photometry
  81. GRB030429, BVRcIc field photometry
  82. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
  83. GRB030329: RTT150 optical observations and upper limit for a host
  84. GRB030329: RTT150 optical observations and upper limit for a host
  85. GRB 030429: redshift from VLT spectroscopy
  86. GRB030501: TAROT candidate afterglow present in archival images
  87. GRB 030429: confirmation of afterglow candidate
  88. GRB 030329 Oprical observations in Rozhen observatory
  89. GRB030329, SPM optical observations
  90. GRB 030329, the review of the sky area in plate archive (1950-1998)
  91. GRB 030329: wide-field photograph by R. Tamura 1 hr after the burst
  92. GRB030329: optical polarization
  93. GRB030329, optical observation
  94. MASTER:optical observations GRB030418
  95. MASTER:optical observations probable GRB030414
  96. GRB030418: Upper limits from recent and historical observations.
  97. GRB030418: Kiso near infrared observations
  98. GRB030329: Optical Observations
  99. OT GRB 030329: early spectrum
  100. GRB030329, optical position

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